This invention relates to test instruments, and in particular to instruments for automatically separating out any one or more of the components of fluff in order to establish and measure the quality of the fluff.
Absorbent products such as disposable diapers and feminine hygiene pads are conventionally manufactured around pads made of "fluff". Fluff is a collection of wood pulp fibers which may be formed into a pad shape, depending upon the particular intended use, by suitable apparatus. If it is recycled fluff, it also may include bits of reclamation waste, such as plastic or other materials from the fluff-based items being recycled. The fluff with the greatest absorbency is the fluff which is most highly fiberized, that is, the fluff in which the greatest number of fibers are separated from each other without breaking the fibers into smaller pieces, called "fines". If the fibers are broken into smaller pieces the absorbency is reduced. If the fluff is not completely fiberized, the remaining bits of wood pulp are called "knots", and again the absorbency of the produced pad is lowered. "Fiberization percentage" is the percent by weight of a particular sample of fluff which is fiberized, the remainder consisting of knots, fines and possibly reclamation waste. That is, the fiberization percentage is arrived at by separating the fluff fibers from the other components in a particular sample of pad, and dividing the weight of the fibers by the weight of the total sample.
There are a number of companies that offer the service of testing fluff to determine the fiberization percentage. Several such companies offer these services as an adjunct to their main business of selling pulp to the papermaking and paper converting industries. One such company is Buckeye Cellulose Corporation of Memphis, Tenn. The apparatus used by this company for conducting this testing consists of a chamber to which a vacuum is applied. An ASME testing sieve of a pre-determined mesh is placed over the chamber. A sample of fluff is placed on the sieve. The sample is agitated by use of a compressed air hose. The operator uses the air from the hose to agitate the sample until only the knots remain above the sieve. The knots are recovered and weighed to determine the complement of the fiberization percentage or, as that company calls it, the disintegration percentage.
The problem with this method and apparatus is that there is a great deal of hand work involved in the testing. This type of testing is therefore not easily reproducible, and several tests conducted on samples taken from the same collection of fluff can result in widely differing test statistics if the operator is not highly skilled. In addition, there is demand for an apparatus which can separate out any one or more of the components of the fluff.
The invention relates to improvements over the apparatus discussed above and to solutions to the problems raised thereby.